Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > comp.lang.c > #22509

Re: Design decisions

Show all headers | View raw

On 06/21/2012 05:02 PM, BartC wrote:
> "jacob navia" <jacob@spamsink.net> wrote in message 
> news:jrvvlb$8k1$1@speranza.aioe.org...
>> In the new "templated" form of the containers library I have now that all 
>> data retrieving functions return the data directly:
>>
>> int (*GetElement)(intList *l,size_t idx);
>>
>> The problem is that it is not possible to return an error
>> with this configuration: Since the return value is an
>> int, any error code could be actually some data!!
>>
>> The solution is to return a pointer to the data and NULL
>> if there is an error, as the other functions of the library do.
> ...
>> What do you think?
> 
> How does C++ deal with it?

Of the C++ standard containers, only basic_string, array, deque, and
vector containers have a close equivalent of GetElement. The other
container types do not provide int-indexed access. The ones that do,
each have two GetElement equivalents. If Container is one of those
templates, then given the declaration:

	Container<T> container;

the expressions container[idx] and container.at(idx) both have the
semantics of *(container.begin()+n). If idx is out of range,
container[idx] has undefined behavior; container.at(idx) throws
std::out_of_range.

Back to comp.lang.c | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

Design decisions jacob navia <jacob@spamsink.net> - 2012-06-21 22:19 +0200
  Re: Design decisions Andrew Cooper <amc96@cam.ac.uk> - 2012-06-21 21:43 +0100
  Re: Design decisions "BartC" <bc@freeuk.com> - 2012-06-21 22:02 +0100
    Re: Design decisions Gareth Owen <gwowen@gmail.com> - 2012-06-21 23:23 +0100
      Re: Design decisions jacob navia <jacob@spamsink.net> - 2012-06-22 09:12 +0200
        Re: Design decisions Ian Collins <ian-news@hotmail.com> - 2012-06-22 19:44 +1200
          Re: Design decisions "Joe." <antelope3@news.net> - 2012-06-25 00:32 -0600
        Re: Design decisions gwowen <gwowen@gmail.com> - 2012-06-22 01:00 -0700
          Re: Design decisions jacob navia <jacob@spamsink.net> - 2012-06-22 10:08 +0200
            Re: Design decisions Gareth Owen <gwowen@gmail.com> - 2012-06-22 17:18 +0100
              Re: Design decisions jacob navia <jacob@spamsink.net> - 2012-06-22 18:27 +0200
                Re: Design decisions Ian Collins <ian-news@hotmail.com> - 2012-06-23 08:44 +1200
                Re: Design decisions jacob navia <jacob@spamsink.net> - 2012-06-22 23:58 +0200
                Re: Design decisions Ian Collins <ian-news@hotmail.com> - 2012-06-23 10:21 +1200
                Re: Design decisions jacob navia <jacob@spamsink.net> - 2012-06-23 02:13 +0200
                Re: Design decisions Ian Collins <ian-news@hotmail.com> - 2012-06-23 12:59 +1200
                Re: Design decisions jacob navia <jacob@spamsink.net> - 2012-06-23 11:03 +0200
                Re: Design decisions Ian Collins <ian-news@hotmail.com> - 2012-06-23 21:52 +1200
                Re: Design decisions jacob navia <jacob@spamsink.net> - 2012-06-23 12:32 +0200
                Re: Design decisions Gareth Owen <gwowen@gmail.com> - 2012-06-23 13:54 +0100
            Re: Design decisions "Joe." <antelope3@news.net> - 2012-06-25 00:36 -0600
          Re: Design decisions jacob navia <jacob@spamsink.net> - 2012-06-22 10:42 +0200
            Re: Design decisions Gareth Owen <gwowen@gmail.com> - 2012-06-22 17:18 +0100
            Re: Design decisions jacob navia <jacob@spamsink.net> - 2012-06-24 18:32 +0200
    Re: Design decisions James Kuyper <jameskuyper@verizon.net> - 2012-06-21 18:43 -0400
      Re: Design decisions "Joe." <antelope3@news.net> - 2012-06-25 00:40 -0600
    Re: Design decisions "Joe." <antelope3@news.net> - 2012-06-25 00:28 -0600
  Re: Design decisions "io_x" <a@b.c.invalid> - 2012-06-22 08:35 +0200
  Re: Design decisions Neil Cerutti <neilc@norwich.edu> - 2012-06-22 12:40 +0000
    Re: Design decisions gwowen <gwowen@gmail.com> - 2012-06-22 06:01 -0700
      Re: Design decisions Neil Cerutti <neilc@norwich.edu> - 2012-06-22 14:26 +0000
    Re: Design decisions Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-06-22 14:01 +0100
    Re: Design decisions David Resnick <lndresnick@gmail.com> - 2012-06-22 06:13 -0700
  Re: Design decisions Jens Gustedt <jens.gustedt@loria.fr> - 2012-06-22 19:05 +0200
  Re: Design decisions "Joe." <antelope3@news.net> - 2012-06-25 00:27 -0600

csiph-web